Torque converter transmission control



APrll 13, 1954 M. c. ROBINSON ToRQuE CONVERTER TRANSMISSION CONTROL Filed Sept. 2l, 1949 RRQ@ l \NN\ NNN .NNY NNN NN N MwN N NN \NT I. a 4 \W\ NNN. \\\Q JEH Patented Apr. 13, 1954 UNITED STATES PATENT GFFICE 2,675,102 TORQUE CONVERTER TRANSMISSION CONTROL MauriceiC. Robinson, Royal Oak, Mich assignor to Chrysler Corporation, Highland -Park, Mich., a.` corporation of Delaware Application September 21,1949, Serial No. 116,926

(Cl.` 192-.0'7l

`13.Claims. l

This inv-ention relates to a hydrokinetic power transmitting unit particularly adapted for use in motor vehicle drive, the` transmitting unit having associated therewith a simplied form of speed responsive control system.

, It is a primary object of this invention to provide a transmission unit comprising a torque converter unit 'having a relatively .high torque multiplying ratio in .combination with a .simplied form `of reverse and direct drive gear unit wherein normally only the higher torque multiplying ratios of the converter unit are used for .starting acceleration in the lower speed ranges afteriwhichthe transmission control system semi-automatically effects a lock-up of the torque converter unit so as to provide a positively connected, cruising, forward, vdirect drive. Thecontrol system also includes means whereby the cruising ,direct dri-ve may be kicked down by the operator from ythe direct drive in the higher speed ranges to a torque multiplying, accelerating, drive `to provide a high speed accelerating ratio utilizing the vlower torque multiplying ratios of the converter unit. This transmission control system .also includes means whereby the direct drive may be automatically downshifted to the starting, low speed, high torque multiplying, acceleratingratioat the most advantageous point.

It is an additional object of this-inventionto provide a transmission unit ycomprising a hydrokinetic. torque converter in combination with a simplilied form of gear unit wherein the torque `converter is normally `used only in its higher torque multiplying ratios where its advantages are most significant and thereafter `the torque converter unit is by-passed and `a positive, twoway, forward drive provided for the cruising speed range, `the lower torque multiplying ratios of the torque converter being reserved for use as a` driver activated accelerating ratio for-emergency use or high speed acceleration.

It is a further object. of this invention' to provide an elicient. flexible, simpli-ed form of powerftransmisson unit having a .control system that is characterized by simplicity andsmoothness of operationduring speed `ratio changes;

It is another object ,of this` invention to `pro-- vide -a power transmitting unit including a hydrokinetic` torque multiplying device wherein speed sensitive controls alone are .utilized for .effecting the automatic changes in the :speed ratio drive transmitted by the power unit,` the speedsensitive controls being arranged such that theyfmay beioverruled` by driveroperated,ccn-l 7 trols to provide means for improving the `flexibility and overall operating characteristics of vthe power transmitting unit.

. It is still another `object of this invention to Iprovide a control system for a power transmission-unit including a torque converter and clutch means. to positively connect the driving and driven members of the torque converter wherein automatically operated speed sensitive control means attempt to automatically effect engagementand disengagement `of, the clutch, the automatically operated control means having associated `therewith driver operable control means to delay or advance 1the time of automatic engagement and disengagement of the clutch.

`Other objects and advantages of this invention will becomereadily apparent from a reading of the. attached specication and a consideration of ther-elated drawings wherein:

Figure 1 is .a diagrammatic View partly in sectionalelevation of thepower transmission unit and the control system therefor embodying this invention; ,and

Figure 21is a graph that discloses certain operating characteristics of this power transmission; unit, the graph showing the torque multiplying ratios of ,the converter plotted against vehicle speed.

The finvention disclosed herein relates to a l Amodified form of .control `for the` power trans- .mitting unit disclosed .in the copending applications of Frederic W. Slack, Serial No. 84,435, filed March 30, 1949, and Serial No. 114,636, led ySeptember 8 1949'.

Figure 1` of the drawings diagrammatically discloses a hydrokinetic torque converter unit A operatively associated with a planetary gear unit. B. Converter unit A is adapted to drivingly connect a prime mover such as a motor vehicle engine toa driven member such as the transmission input shaft i6 `of the gear type Vtransmission .unit B, subsequently described in :detail The reference numeral 8; represents an rend-portion of a driving member, such as the `engine crankshaftof a motor vehicle power unit. The shaft 8 is drivinglyconnected to the torque converter casing t3 within `which are mounted the various 'converter components, namely, the limpeller member 14, the `turbine or runner mem- -aber ;l5and the guide wheel or reaction member .lf-l.

The vaned impeller wheelwld is iixedly connected to the converter casing I3 and is accordingly adapted tobe rotatably driven `by `the `driving shaft 8. The vaned turbine lwheel l5 of the guide wheel hub portion lla that is rotat ably mounted, by means of a v one-way brake device 2 I, on an axially extending sleeve 32 that is fixed to and projects from the rearwardly positioned, relatively stationary, gear box housing 42.

The one-way brake 2l will permit only forward rotary movement (clockwise when locking from converter A rearwardly towards .gear box B) to be transmitted to guide wheel Il by the forward rotation of the impeller I4, the brake 2| preventing rotation of the guide wheel Il in a reverse or counterclockwise direction.

The torque converter unit A (see Fig. 1) includes a gear type oil pump that has a driving gear that is directly connected to the axially extending flange portion I3b of the rotatable converter casing I3. The pump 25 draws oil from a sump and circulates it through the converter unit A,the transmission lubricating system and the various hydraulically operatedcontrol mechanisms associated with this transmission uniti i The circulation of oilthrough the converter A, by the pump 25, provides a means for maintaining the converter full of oil whenever shaft 8 is rotating. Furthermore, this circulation of the working fluid throughv the converter and the lubricating and hydraulically operated control systems provides a means for cooling the converter fluid.f Separate oil cooler means 1.46, subsequently described, are also provided. A second pum-p '14, driven by the transmission output shaft' l I, is also included in this transmission to provide a source of pressure fluid when the engine is not operating even though the output shaft is -rotating. This pump 74 will be more fully described in connection with the planetary gear box B.

In order to provide means for transmitting a positive,twoway, direct drive from the driving shaft 8 to the intermediate shaft I5 a torque conl verter lock-up clutch C is provided. The lock-up clutch C includestheradially extending, friction surfaced disc member 33, which member is drivingly connected to the intermediate shaft I6. Cooperatively associated with the disc 33 is a hydraulically operated clutch piston 35 which is .slidably mounted on the intermediate shaft I5 for y axial shift with respect thereto.

Casing I3 is formed -With a cylinder 3l in whichpiston 35 is engaged clutch position. It will be noted that when the clutch piston 35 has been moved rearwardly to clampingly engage the disc member 33 with the backing plate 38 then the torque converter impeller member I4 and the turbine member I5 are locked rtogether and a positive direct drive is transmitted from the `driving shaft Bto the intermediate shaft I6. This direct drive bypasses the torque converter unit A and provides a highly efficient, non-slipping drive that can be used for engine braking during coast drive. The control system associated with the transmission unit is arranged such that the lock-up clutch C 5 may be engaged after the torque multiplying effect of the converter has dropped from its starting drive, high torque multiplication ratio but before the converter unit begins to function as a fluid coupling. By such an arrangement the torque multiplying effects of the converter unit are most advantageously used. With the particular arrangement herein disclosed the torque converter A is designed to have a starting drive torque multiplying ratio of approximately 3 to 1 and the lock-up clutch C is arranged to be semiautomatically engaged when the torque multiplying ratio has dropped to approximately 2 to 1 or less. One of the reasons for effecting a lock-up of the torque converter A by clutch C prior to the time the converter unit begins to function as a simple'fluidcou-pling is to provide a torque multiplying ratioy of approximately 2:1 that may be brought intoY operation by a normal kickdown from the cruising direct drive. This feature is more fully explained in the subsequent description of the operation of this transmission unit.

, The gear box B includes the planetary type reverse gearing 5I and the planetary unit direct .drive clutch mechanism D. Rotatably mounted .on the rear end of the housing sleeve 32 isthe hub portion of the reverse gear planet pinion carrier y5?. Pinion carrier 52 has a peripheral flange portion adapted to be releasably engaged by a braking band 53. Pinion carrier 52 has pinion pins 54 to rotatably support a plurality .of planet pinion gears 55. Fixed to the rearwardly extending end of intermediate shaft I5 is the sun gear 56 of the reverse gearing 5I. Sun gear 56 is arranged to meshingly engage the planet pinion gears so as to eect rotation thereof. Alsol meshingly engaging the planet pinion gears 55 is the annulus gear 51'. Annulus gear 51 is drivingly connected to the drum member 62 of the clutch D. Drum 62 is xedlycon- 4 Vnectedto the output shaft 'I I.

Direct drive-clutch D includes the drum member 62, the driving hub member 614 and the axially shiftable piston member 66. Drum.member 62 has drivingly mounted thereon the friction discs 63 which are adapted to be releasably engaged with the friction discs 65 drivingly mounted on the hub member 64. Hub member 64 is drivingly connected to the rear end portion of intermediate shaft I6. The Vaxially shiftable piston 56 is adapted to be moved forwardly to effect engage- `,ment of direct drive clutch D as a result of the admission of pressure fluid to the cylinder bore 68 in the cylinder-like drum member 62. Eressure fluid is admitted to the cylinder bore S8 through the conduit IBI which is subsequently described. Spring means (not shown) normally urges the pistonmember 65 rearwardly to a disengaged clutch position.

It is thought to. be obvious that when direct drive clutch D is engaged and the band 53 of the planetary' reversing gear mechanism 5i is released, then drive Will be transmitted directly from intermediate shaft I 5 to output or driven shaft II through the engaged clutch members 64, 65, 63,` 62. At the times torque converter lock-up f clutch C 4and direct drive clutch D are both en- .gaged then a positive, two-way', direct drive is transmitted from driving shaft 8 through intermediate'shaft I6'to driven shaft 'il by a power transmitting trainthat by-passes the torque conis rotating.

farmaci verter unit A'and thefplanetaryugearing 51|. Such a drive is highly efficient for cruising drive for it eliminates theslip thatisinherentin ahydrokinetic torque converter unit andit-also provides a positively connected power transmitting train that willprovide engine braking `for coast drive. Clutch D is always engaged before forward drive is transmitted-to 'the driven shaft 1 I bythe transmission unit 'and this clutch D remains engaged during all forward drive; As a result of this rarrangement whereby there is noengagement or disengagement of clutch D during forward drive, a very smooth drive is obtainable.

Driving-ly connected to the output shaft V1 is a second gear type oil pump 14. Oil pump 11| is arranged to draw fluid from a suitable supply sump and circulate it through the hydraulically operated control and lubrication systems of the transmission unit whenever the output shaft 1| Consequently, pump 1'4 provides pressure fluid for operation of the transmission unit during a pushed or towed start even if engine driven pump 25 is inoperative due to a dead engine. Suitable controls, such as the pressure regulator valve |25 may be provided to have pump 14 automatically take over the. supply of pressure Vfluid for the transmission unit whenever the speed of output shaft 1| exceeds a certain predetermined value thereby relieving the front pump 25 of its working load after the engine unit (not shown), has ybegun to drive the transmission output shaft 1|. This arrangement whereby the front pump 25 merely by-passes lubricant during most of the driving time relieves the engine of a material load and improves operating efciency.

Also drivingly mounted on the output shaft` 1| is a drive pinion 15 that transmits drive from shaft 1| to the driven shaft 1,1 of the speed responsive, centrifugal force operated governor mechanism 16. Governor 16 provides the means for automatically controlling operation of the torque converter lock-up clutch C. Governor 16 is associated with the pressure fluid control valve 853 of the hydraulically operated transmission control system in such a manner thatithe lock-up clutch C will be automatically operated in a manner to provide highly eiiicient vehicle performance. The governor mechanism 16 herein disclosedis preferably designed so that on acceleration of the vehicle driven by this power transmission unit the governor will attempt to cause engagement of lock-up clutch C when the vehicle has attained a road speed of approximately twenty-five miles per hour. However, on deceleration of the vehicle the governor will not effect disengagement of clutch C until the vehicle road speed has dropped to approximately twelve miles per hour. By providing a governor that disengages clutch C on deceleration at a relatively low road speed, compared to its point of activation on acceleration, itis possible to maintain the transmission unit in its cruising direct driveratio during the major portion of its cruising drive and the automatic shifts between direct cruising drive and the torque converter transmitted accelerating drive are maintained `at a minimum. This tends to improve operating eiciency and to give smoother performance.

The hydraulically operated transmission control system shown includes the conduits and` H6 which connect the pumps 25 and 14 respectively with a pressureregulator valve |25. Spring i of pressure regulator valve |25 determines the pressure that is to be maintained in the, pressure uid supply conduit |28. A pump output pres- `sure of approximately 9G pounds Ypersquare inch has -been found to be satisfactory for operationrof thistransmission control system. However, the actual pressures of the iiuid delivered to supply conduits |28 and |36 may be varied hy the control` of pressure fluid admitted to conduit IBI. As this lpressure control feature relates to operation of the pressure regulator valve` |25 which element does not form a part of this invention, additional description of theV valve |25 will be omitted. The pump output conduits I I5 and |-I6 each include check valves ||1 and Il!! to insure a suitablepressure head in the pumps at all times. With the control arrangement shown the pump 25 supplies the fluid pressure for starting drive under ordinary conditions and as the speed of output shaft 1| increases the pump 14 automatically takes over and feeds the supply conduit |28. As pump 14 comes into operation the pressure fluid supplied therefrom is transmitted to chamber |21 of pressure. regulator valve |25 and this pressure acts on land |29@ of piston valve |29 and moves piston valve |29 towards the left compressing spring |26. Movement of piston valve |29 to the left displaces the valve land |2919 so as to connect conduit |3| to .by-pass conduit |32 thereby providing a means for fby-passing 'the output of the pump 25. Upon the operation of either pump 25 or 1t the fluid pressure in chamlber |21 is always sufiicient to move plunger valve |29 slightly to the left to connect chamber |21 with conduit |35` which supplies pressure fluid for tho operation of the torque converter unit A and the lock-up clutch C.

The pressure fluid supply conduit ist connects the chamber |21 of the regulator valve |25. to the cylinder 86 that contains the control valve 88. The control valve 88 is slidahly mounted within the valve cylinder bore S6 so that it may be reeiprocated as a result of energization and deenergization of the solenoid d2. Solenoid 22 has a reciprocable plunger bar es that shifts towards the left and actuates valve S3 on energize.- tion of the solenoid 82. Energization of solenoid 82 moves valve 8B to the left to the position shown in Figure l where the valve lan-:l Sta of the valve 88 will block oif the supply of pressure fluid to conduit Ill from the supply conduit |35. Ac-

cordingly, when solenoid S2 is energized pressure fluid cannot reach `the torque converter lock-up clutch C so the drive from shaft 8 to shaft Iii will be a torque multiplying drive through the converter A, When valve S3 is positioned as shown in Figure l,then the pressure fluid in clutch C can drain back to a supply sump through the drain port ,39. On deenergization of the solenoid 82 the valve return spring 9| shifts the valve 38 to the right to a position where supply conduit I 36 is connected through the valve cylinder 86 to the conduit and pressure fluid is then directed into the lock-up clutch C to effect engagement of the clutch. At this time valve land 83h will block oi drain 89 and maintain the pressurized condition of the pressure` fluid in the clutch C. It willibe noted that during all operation of the transmission pressure fluid is directed into the torque converter A from supply conduit |35 through the branch conduit i3d' Conduit` 31 has a restriction passage I31c to control the volume of the fluid admitted to the converter A and a suitable pressure relief valve i3d is associated with the discharge side of the converter A to maintain the proper'pressureY within theconverter A. Pressure fluid within the converter A is maintained at a sufficiently low pressure so prior to its return to the supply sump for the pressure fluid system.

The control system -for the operation of the solenoid S2 and control valve 38 includes a pair of solenoid energizing circuits and a solenoid deenergizing circuit, all three circuits being arranged in parallel.

The first circuit for controlling energization of solenoid82 and operation of control valve 88 includes an automatically operated switch 92.

Automatically operated switch Q2 is arranged to be operated by the speed sensitive governor mechanism i6 which'is preferably drivingly connected to the transmission output shaft 'H through the rotatable governor shaft 'VE that meshingly engages the pinion l5 fixed to the output shaft 'i I. Rotatable governorl shaft Vl carries a pair of pivotally mounted weights T8 that are adapted to swing radially outwardly about their pivot centers 'i9 as the speed of shaft 'H increases.

After a predetermined outward movement of weights 18 the fingers on the inner sides of the weights 18 engage the collar on shaft 85 and raise the shaft 80 to a position that causes switch 92 to open and this breaks one of the electrical circuits for controlling the operation of the solenoid Obviously when switch 92 is open then the circuit from the grounded battery H5 through the ignition switch |76, solenoid 32, conductor 84, and switch 92 to ground at l'll is no longer effective to maintain solenoid 82 energized.

The second circuit for controlling energization of solenoid 82 includes a manually operated switch, which is meant to include either a hand or foot operated switch, such as the switch unit 93, which switch unit is arranged in parallel with the automatically operated switch 92 so that it can modify the operation of switch 92 and provide a means for the driver to overrule the automatic operation of solenoid 32 by the switch 92. Switch unit 93 has a contact 93a thereof connected by conductor 94 to a switch contact 95a associated with solenoid 82. Contact @da is adapted to be engaged by a switch contact 33h carried by the solenoid bar conductor element 63a whenever solenoid t2 is energized. Conductor element 83a f of the solenoid plunger bar 83 also includes a contact 83o that is adapted to be engaged with the contact 82o of the solenoid coil whenever solenoid 82 is energized. Conductor 84 connecting solenoid 82 and switch 92 has a branch conductor 85 connected to ground at IB through a pair of switch contacts 35a. Contacts 85a are adapted to be connected together by a conductor element l98d carried by a manually operable plunger member 98. Plunger member @S is arranged to be actuated by means of the accelerator pedal 95 that controls the torque delivered to the transmission driving shaft ii. Accelerator pedal 95 is connected by linkage et to a pivotally mounted bell crank lever Si. Lever 9'! has a cam formation on the end of one of its arms that engages an end of the plunger E38 to transmit motion thereto. Spring 99 normally urges conductor ele.. ment 98a downwardly to break the connection between contacts 85a. When the accelerator Vpedal is in the closed throttle or idle position indicated by the letter I then the spring 99 urges plunger 98 downwardly to the position shown in Fig. 1 where the connection between contacts 85a is broken. In this position the shoulder 98h on plunger 98 engages the spring supported conductor element lfl and moves it downwardly so as to break the connection between contacts 93a. Accordingly at the closed throttle or idle position I of the accelerator pedal 9e the solenoid 82 can not be grounded at |18 through either of the conductors 85 or 94 Vfor both sets of contacts 85a and 93a are open. However, at closed throttle the speed of shaft 'Il will normally be such as to cause the governor controlled contacts S2 to be closed so a closed circuit to ground at lll is always available to energize the solenoid 82 and initiate drive through the torque converter A. Upon movement of the accelerator pedal 95 from its closed throttle position I to its wide open throttle position W there is provided asecond circuit for eiecting energization of solenoid 82 for then a circuit in parallel with the first energizing circuit is provided from battery I`l5 through switch E76, solenoid 82, conductor S5 and closed switch contacts 85a to ground at l'8. This second circuit will permit energization of solenoid 82,1'egardless of the condition of the governor operated switch 92 for it is in parallel with the first energizing circuit containing the switch $2. Consequently a so-called manually or driver effected energization of solenoid 32 may be accomplished at any vehicle speed. llhis permits a kies-down from direct drive 'to an accelerating drive through the converter unit A at any speed as will be more clearly pointed out in the subsequent description o the operation of this transmission unit.

The circuit for controlling de-energization of the solenoid 82 is arranged in parallel with and is adapted to cooperate with the automatically operated first solenoid energizing circuit through the switch 92. This solenoid de-energizing circuit comprises the battery |15, switch li, solenoid 82, contacts 820, 94a, the solenoid actuated contact connecting element 83u, conductor SI1, contacts 93a, the accelerator pedal actuated contact connecting element li and the ground connection at I'8. The operation of the solenoid deenergizing circuit is also fully explained in the subsequent description of the operation of this transmission unit.

The manual controls for this transmission unit include the drive selector lever ill! which is usually rotatably mounted on the conventional vehicle steering column i652. Control lever I4! is connected to manually operated piston type control valve EM by the linkage arrangement It.v Drive selector lever lill has three positions, a centrally located neutral position, between the terminally located forward drive position and the reverse drive position. The three positions are denoted by the letters N, DR and R respectively.

Operation When the transmission driving engine is operating and drive selector lever mi is in the neutral position then manual control valve M4 is positioned so that supply conduit 28 cannot direct pressure fluid into either the forward direct drive drive is transmitted to the output shaft il.

iluid through the converter Anand the lubrication system. The torque converter lock-up` clutch C will be disengaged at this time for the ignition system has energized the solenoid S2 due to' the governor "i6 causing contacts 92 to be closed at all vehicle speeds under approximately twelve miles per hour. With solenoid 82 energized the control valve 88 is shifted towards the left to the position shown and consequently pressure fluid from conduit |36 cannot enter the conduit Hl nor the clutch C.

If the drive selector lever UH is moved to the forward drive position (as shown in Fig. l) then pressure fluid from supply conduit t28 passes through the manually operated control valve assembly Mii into conduit lill from which the pressure fluid will be directed into the conduit Iiii so as to engage direct drive clutch D and condition gear box B for the transmission of a forward direct drive. The speed at closed throttle with. the valve Ulli in its forward drive position Will be such that slip in the torque converter unit A and drag of the associated. drive `train elements will prevent an actual forwarddrive being transmitted to the driven shaft 'il even though the direct clutch D is engaged. Subsequently, vas the accelerator pedal is depressed to increase the speed of the driving engine unit (not shown), the torque converter impeller le will be rotated at such a speed thata torque multiplying drive will be transmitted to the converter turbine .I5 and the associated driven shaft 1.5. Shaft i6, being directly connected to output shaft ll by the direct drive clutch D,` thus initiates drive of shaft 'll at a torque multiplying ratio which is particularly adapted for vehicle acceleration. Accordingly, during initial forwardacceleration the relatively high torque multiplication ratio of the converter unit A is, eifective and a torque multiplying `accelerating drive of approximately 3 to 1 is transmitted by the converter unit A to the output shaft ll. This drive is from driving shaft 3 through torque converter A to turbine driven shaft I5 and then through engaged direct clutch D to output shaft 1l.

Subsequently, as the accelerator pedal 95 is depressed from` idle position towards open position O, the speed of output shaft Il increases and the speed responsive governor 'Hwill operate so as to condition the control system for the engagement of the torque converter lock-up clutch C which will convert the accelerating, relatively high torque multiplying, starting drive into a t\voway, positive, direct drive. At a predetermined speed of output shaft ll', approximately twenty-five miles per hour vehicle speed, the governor 'FE will open switch 92 and break the solenoid energizing circuit that is grounded at |11. However. opening of switch 92 will not automatically deenergize the solenoid B2 and effect the engagement of lock-up clutch C for on depression of accelerator pedalre the plunger harta is raised and this raises the shoulder 98h of bar 98 off the conductor member liti! and permits spring 102 to urge conductor tell against contacts 93a `of switch s3. Closing of switch contacts 93o by conductor It provides a closed solenoid energizing circuit to ground at H3 which circuit is in parallel with the opened circuit through switch 92. Therefore solenoid B?. will remain energized after switch QZ'opens as long as contactsV 93a are closed. Contacts 93a will remain closed until the accelerator pedal is released to the closed throttle or idle :position `l. `On Vrelease of theeccelerator lpedal 95,130 its closed throttle position the plunger bar shoulder 98h will depress conductor |00 and open contacts l93a to .break the solenoid energizing circuit through contacts 93a that is grounded at H8. This de-.energizes the solenoidrBZ and control valve SB then shifts to the right to admit pressure fluid to the clutch C and convert the torque multiplying drive through converter A into a positive two-Way direct drive. Subsequent depression of the accelerator to any position between I and O, the normal cruising speed ranges, will not re-energize the solenoid 82 for the conductor 33a has been shifted to the right by spring` 9i so that contacts 32o and 94a are open and consequently neither ground at II'l or |18 is available to complete the energizing circuit for solenoid 82. The converter lock-up clutch C Will thus normally remain engaged until the speed. of the vehicle drops to approximately l2 miles per hour at which time the governor 'i6 will close switch 52 and energize the solenoid 82 so as to automatically disengage the clutch C `and =rem establish the torque multiplying drive throughl the converter A. From the above it is thought to be obvious that a control system has heenpro.- vided in which the conversion from the acceleratingA torque multiplying drive to the positive direct drive may be delayed .at the `will of the vehicle operator until the most favorable time for such a change is reached. This control systemis a combination of an automatic speed `responsive shift with a manuallyoperable shiftdelaying arrangement to provide a; most iiexiblefcontrol sys tem wherein the vehicleoperator may condition the transmission to meetthespecific lroad, load and tra-uic conditionsoencountered.

In nor-mal operation of the vehicle the ac,- celerator pedal 95 is Amoved between the closed throttle -or idle position I and the open throttle position() which ispreferably 5 `or 10 degrees less than the fully opened-or Wide open throttle position W of the pedal `t5. During this normal arc of operation ofthe accelerator pedal 95 the plunger bar mounted` conductor 98a will not engage the contacts `85d so the kickdown to a converter transmitted drive Willlnot occur by a normal depression of pedal .95. To prevent accidental or unintended depression of the accelerator pedal to the Wide open throttle position W a pick-up spring i `is associated withpedal 95 so as to require additional eilort on the part of the operator to depress the pedal a5 to the position W whereby ailrickdovvn of the locked-up converter clutch C' will occur. Spring H35 is not engaged by the pedal 95 until after the pedal has been depressed to the nearly Wide open throttle position O.

If, while travelling in the two-way, locked-up, direct drive, a high speed Aaccelerating drive is desired then a idol/:down to a more favorable accelerating ratio may be `manually eifected by merely depressing the accelerator pedal 95 a predetermined amount, such as to the limit of its downward or throttle opening movement as indicated by the letter W, and this will effect. a closing of switch contacts 85a 'oy-conductor 98a and` thereby provide a closed circuit to ground at VEB to energize the solenoid 82 and cause a shirt of control valve e8v to the left so as to disengage the torque converter lock-up clutch C and bring the torque converter unit A back into operation. When `coiuzluctor 98a closes contacts a circuit from solenoid S'Zthrough conductors 84, 85, 85a to ground at V18 is provided which circuit is independent of the `position of the solenoid plunger bar conductor 83 `therefore the fact that ll solenoid 82 is vde-energized prior to the kick down is immaterial. From `Fig. 2 it will be noted that when the vehicle speed is above the speed at which lock-up of the converter unit A ncrmally occurs, still, there is a considerable torquemultiplication ratio available for high speed accelerating use so it is possible to overrule the automatically operated speed responsive governor 16Vand to manually kickdown from the cruising direct drive to a torque multiplying drivethrough the converter unit A at any time up to approximately forty miles per hour vehicle speed. At cruising speeds of twenty to forty miles per hour a kicked-down accelerating ratio of between 2 and 1.2 to 1 is available for high speed accelerating drive. The kicked down accelerating ratio may be maintained for as long as the vehicle operator decides the torque multiplying drive is necessary by merely keeping the accelerator pedal 95 depressed to position W. On release of the pedal 95 the lock-up clutch C will be re-engaged V`and the two-way direct drive re-established provided the vehicle speed is above 25 miles an hour .or Whatever speed the governor 1B is set to open the contacts 92.

Reverse drive may be obtained by moving the drive selector lever |4| to the reverse position. This positions the manually operated control valve |44 in such a position that pressure fluid from supply conduit |28 is directed into the reverse band control conduit |5| while forward drive control conduit |01 is blocked off from supply conduit |28. Conduit ||l| at this time is opened to the drain |48 in valve |44 to drain the pressure duid from the direct drive clutch VD. Admission of pressure iiuid to conduit 5| ac- Atuates the reverse band piston |55 and applies reverse braking band 53 so that the planetary gearing 5| will transmit a reverse drive from input shaft 8 through the torque converter A and turbine driven shaft I6 to the planetary gearing 5| and then to output shaft 1|. Planetary gearing 5| yis effective to produce a reverse drivefor application of brake band 53 anchors the planet pinion carrier 52 while driving sun gear 56 rotates the annulus gear 51 in a reverse direction. Annulus gear 51 is directly connected to output shaft 1|, thus a reverse drive is transmittable through the torque converter unit A to the driven or output shaft 1|.

I claim:

l. In a motor vehicle including an engine having an accelerator pedal and a transmission drivingly connected to lsaid engine having driving and driven shafts, a hydrodynamic torque converter conneotible between said shafts to transmitv a torque multiplying drive therebetween, and va clutch associated with said converter adapted to be engaged to provide means for transmitting a positive direct drive between said shafts and to be disengaged to provide means for the transmission of a torque multiplying drive between said shafts through said converter; automatically operated control means responsive only to the speed of the driven shaft to condition the control system for said clutch for a driver effected clutch engagement after said driven shaft has accelerated to a predetermined rotative speed and to automatically effect disengagement of said clutch after the speed of said driven shaft has decelerated to a speed less than said predetermined rotative speed, and a rst driver operable control means for said clutch adapted to be actuated on release of said accelerator pedal to provide' a means to effect the engagement of said clutch after said driven shaft accelerates to said predetermined rotative speed and a second driver operable control actuated by movement of said accelerator pedal to provide a means for effecting disengagement of said clutch prior to time said automatically operated control means would eect such disengagement, said first driver operable control means thereby providing a means cooperable with the automatically operated control means to control and vary the period of the torque multiplying drive and said second driver operable control means providing a means to overrule the automatically operated clutch disengaging control means and providing a driver operated means for controlling the period of transmission of the positive direct drive.

Y 2. In a motor vehicle including an engine with an accelerator pedal and a transmission driven by said engine having driving and driven shafts, a hydrodynamic torque converter having a torque multiplying ratio of approximately 3 to 1 connectible between said shafts to transmit a torque multiplying drive therebetween, and a clutch associated with said converter adapted to be engaged to provide means for transmitting a positive direct drive between said shafts and to be disengaged to provide means for the transmission of a torque multiplying drive between said shafts through said converter; automatically operated control means responsive only to the speed of the driven shaft to condition the control system for said clutch for a driver effected clutch engagement after said driven shaft has accelerated to a predetermined rotative speed and to automatically effect disengagement of said clutch when the speed of said driven shaft has decelerated to a speed lessrthan said predetermined rotative speed, and a first driver operable control means for said clutch adapted to be actuated by release of said accelerator pedal to engine idle position to provide a means to eifect the engagement of said clutch after said driven shaft accelerates to said predetermined rotative speed and a second driver operable control means actuated by depression of said accelerator pedal to provide a means for effecting disengagement of said clutch prior to time said automatically operated control means would effect such disengagement, said rst driver operable means thereby providing a f means cooperable with the automatically operated control means to control the period of the torque multiplying drive and said second driver operable means providing a means independent of said automatically operated control means 4to provide a driver operated means for controlling the period of transmission of the positive direct drive, said automatically operated control means including a pressure fluid supply system having conduit means arranged to direct pressure uid into said converter and into an operator for said clutch, a speed responsive governor operably associated with said driven shaft, valve means operably associated with said governor and adapted to be automatically actuated by valve operator mechanism operably associated with said governor, said valve means forming a part of the pressure fluid supply system and controlling admission and release of pressure fluid to said clutch fluid pressure operator to thereby eil'ect engagement and disengagement of said clutch, said second driver operable control means including means operable by said accelerator pedal to actuate said valve means whereby the driver may effectdisengagement of said clutch prior to america 13` the time said `governor would automatically effect disengagement of the clutch.

3. In a motor vehicle includingan engine having an accelerator pedal and a, transmission drivingly connected to said engine having driving and driven shafts, a` hydrodynamic torque converter connectible between said shafts to transmit a torque multiplying drive therebetween, and a clutch associated with said converter adapted to be engaged to provide means for transmitting a positive direct drive between said shafts and to be disengaged to provide means for the transmission of a torque multiplying drive between said shafts through said converter; automatically operated control means responsiveonly to the speed of the driven shaft to condition the control system for said yclutch for a driver effected clutch engagement after said driven shaft has accelerated to a predetermined rotative speed and to automatically effect disengagement of said clutch when the speed of said driven shaft has decelerated to a speed less `than said predetermined rotative speed, and a first driver operable control means for said clutch adapted to be actuated by release of said accelerator pedal to provide a means to effect the engagement of said clutch after said driven shaft accelerates to said predetermined rotative speed and a second driver operable control means actuated by depression of said accelerator pedal to provide a means for effecting disengagement of said clutchprior to time said automatically operated control means would effect such disengagement, said first driver operable means thereby providing a means cooperable with the automatically operated control means to control the period of the torque multiplying drive and also a meansindependent of said automatically operated control means to provide a driver operated means for controlling the period of transmission of the positive direct drive, said automatically operated control means including a pressureA fluid supply system having conduit means arranged to direct pressure fluid into said converter and into an operator for said clutch, a speed responsive governor operably associated with said driven shaft, a solenoid operably associated'with said governor so as to have the energization thereof controlled by said governor, valve means operably associated with said solenoid for actuation thereby, said valve means forming a part of the pressure uid supply system and controlling admission and release of pressure fluid to said clutch fluid `pressure operator to thereby effect engagement and disengagement thereof respectively, said second driver operable control means including means operable by said accelerator pedal to independently effect the deenergization of said solenoid and the actuation of said valve means for effecting disengagement of said clutch and means actuable by said first driver operable means and coopera-ble with said automatically operated control means to conjointly effect cle-energizaticn of said solenoid and actuationl of said valve means for effecting engagement of said clutch.

4. In a motor vehicle including an engine having an accelerator pedal and a transmission drivingly connected to said engine having driving and driven shafts, a hydrodynamic torque converter connectible between said shafts to transmit a torque multiplying drive therebetween, and `a clutch associated with said converter adapted'to be engaged to provide means for transmittinga positive direct drive between said shafts and to be disengaged toprovide means for the transmission of a torque multiplying drive between said shafts through said converter; automatically operated control means responsive onlyto the'speedof the driven shaftV to condition the control system for said clutch for a driver effected clutch engagement after said driven shaft has accelerated to a predetermined rotative speed and to automatically effect disengagement of said clutch when the speed of said driven shaft has decelerated to a speed' less than said predetermined rotative speed, and a first driver operable control means for said clutch adapted to be actuatedby release of said accelerator pedal to provide a means to effect the engagement of said clutch after said driven shaft accelerates to said predetermined rotative speed and a second driver operable control means actuated by depression of said accelerator pedal to provide a means for effecting disengagement of said clutch prior to time said automatically operated control means would effect such disengagement, said first driver operable means thereby providing a means `coopera'ble with the `automatically operated control means to control the period of the torque multiplying drive andsaid second driver operable means providing a means independent of Ysaid automatically operated control means` to provide a driver operated means for controlling theperiodf transmission of the `positive direct drive, `said automatically operated control means comprising a source of pressure fluid connectedby conduit means to said clutch, the-conduit means including Aa cylinder and a valve movably mounted therein, said valve being adapted to be actuated` to` control the admission to and release of pressure fluid to an operatorfor'said clutchto thereby control engagement and disengagement of saidv clutch, a speed responsive governor operably associated with said driven shaft, a solenoid operably connected to said solenoid so as to have the` energization thereof automatically controlled by' said governor `and the de-energization thereof controlled conjointly by said governor and the first driver operable control means, the second driver operable `control means independently providing a means for the driver to control the energization of said solenoid.

`5. In a motor vehicle including an accelerator pedal and a transmission having driving and ydriven shafts, a hydrodynamic torque converter connectible between said shafts to transmit a. torque multiplying drive therebetween, -and a ciut'ch and controls therefor' associated with said converter, said clutch being adapted to be en gaged to providemeans for transmitting a positive direct drive between said shafts and to be disengaged to provide means for the transmission of a torque multiplying drive between said shafts through said converter; said clutch controls comprising a pressure fluid system for effecting engagement and disengagement of said clutch, a valve associated with said pressure fluid system andarranged such that actuation thereof controls engagen'ient and disengagement of said clutch, a solenoid unit operably associated with said valve in suc a manner that energization andcle-energization of said-solenoid unit actuates said valve, and an electrical control system for effecting energization and de-energization of said solenoid unit comprising first and second solenoid energizing circuits arranged in parallel, said first energizing circuit including a first switch and a governor mechanism responsive to the speed of said driven shaft for automatically opening and closing said first switch, said second solenoid energizing circuit including a second switch and a means operable by said accelerator pedal to provide for the manual opening and closing of said'second switch, and a solenoid deenergization circuit comprising said rst solenoid energizing circuit and a third 'circuit' arranged in parallel with said ilrst solenoid energizing circuit comprising a third switch arranged to be automatically closed during energiaation of said solenoid and opened during de-energization of said solenoid, and a fourth switch in series with said third switch, said fourth switch being arranged to be manually closed during throttle opening movement of said accelerator pedal and to be opened on release olf said accelerator pedal to closed throttle position.

6. In a motor vehicle including an accelerator pedal and a transmission having driving and driven shafts, a hydrodynamic torque converter connectible between said shafts to transmit a torque multiplying drive therebetween, and a clutch and controls therefor associated with said converter, said clutch being adapted to be engaged to provide means for transmitting a positive direct drive between said shafts and to be disengaged to provide means for the transmission of Va torque multiplying drive between said shafts through said converter; said clutch controls comprising a pressure fluid system for effecting engagement and disengagement of said clutch, a valve associated with said pressure uid system and arranged such that actuation thereof lccntrols engagement and disengagement of said clutch, a solenoid unit operably associated with said valve in such a manner that energization and de-energization of said solenoid unit actuates said valve, and an electrical control system for effecting energization and de-energization of said solenoid unit comprising a rst and a second solenoid energizing circuit, said circuits being arranged in parallel and each including a switch adapted to be closed to eiiect energization of said solenoid unit, said rst solenoid energizing crcuit having a governor mechanism responsive to the speed of the driven shaft to automatically close the switch in said nrst solenoid energizing circuit at driven shaft speed below a predetermined speed and to automatically open the switch in the first solenoid energizing circuit after said driven shaft attains said predetermined speed, said second solenoid energizing circuit including a iirst accelerator pedal operated switch adapted to be closed by a predetermined amount of throttle opening movement of said accelerator pedal and to ybe opened when the accelerator pedal is in throttle closing position, and a circuit for controlling de-energization of said solenoid unit comprising a solenoid operated switch that is automatically closed upon energization of said solenoid and opened upon de-energization of said solenoid and a second accelerator pedal operated switch in series with said l solenoid operated switch, said Ysecond accelerator pedal operated switch being arranged such that release of said accelerator pedal to a throttle closing position opens said second accelerator operated switch while a predetermined movement of saidaccelerator pedal in a throttle opening direction closes said second accelerator pedal operated switch.

7. In a control system for a motor vehicle having an accelerator pedal controlled engine and a transmission adapted to be driven by said engine, said transmissionhaving coaxially arranged driving, intermediate and driven shafts, a hydrokinetic torque converter having a torque multiplication ratio of approximately 3 to 1 for transmitting multiplied torque from the driving to' the intermediate shaft, a torque converter clutch' for directly connecting the driving and intermediate shafts, a direct drive clutch for directly connecting the intermediate and driven shafts,V

manually operated means to control engagement of said direct drive clutch, automatically operated, vehicle speed responsive, control means to automatically condition said torque converter clutch for enga-gement and accelerator pedal controlled means to thereafter effect torque converter clutch engagement at the will o the vehicle operator, said automatically operated control means being arranged to automatically cause disengagement of said torque converter clutch when the speed of said vehicle is decelerated below a predetermined value, said accelerator pedal operated means being operable to effect engagement of said torque converter clutch after the speed of said vehicle has been accelerated to said predetermined value and while the torque converter is operating in the higher ratios of its torque multiplication range, and a second accelerator pedal operated torque converter clutch control means cooperatively associated with said automaticallyoperated vehicle speed responsive clutch control means adapted to be operated to provide a means to overrule said automatically operated vehicle speed responsive control means and to provide a second means to effect disengagement of said torque converter clutch, said second means being effective prior to the time said automatically operated vehicle speed responsive control means would automatically effect clutch disengagement, said second accelerator pedal operated control means thereby providing means for the transmission of a torque multiplying drive utilizing the lower ratios of the torque multiplication range of the torque converter.

8. In a control system for a motor vehicle having an engine and a driver operable Vcontrol for said engine, and a transmission adapted to be driven by said engine, said transmission having coaXially arranged driving, intermediate and driven shafts, a hydrokinetic torque converter having a torque multiplication ratio of approximately 3 to 1 for transmitting multiplied torque from the driving to the intermediate shaft, a torque converter clutch for directly connecting the driving and intermediate shafts, a direct drive clutch for directly connecting the intermediate and driven shafts, manually operated control means to control engagement of said direct drive clutch, automatically operated control means responsive to the speed of the driven shaft arranged to provide a means for conditioning said torque converter clutch for engagement after the speed of said driven shaft is accelerated to a predetermined value, and to automatically effect disengagement of vsaid torque converter clutch when the speed of said driven shaft decelerates below a predetermined value, a first control actuable by said driver operable engine control to eiect engagement of the converter clutch after the driven shaft speed has been accelerated to said predetermined value and while the torque converter is operating in the higher ratios of its torque multiplication range, and a second control actuable by said driver operable engine control means and cooperatively associated with said automatically operated control means for disengaging said converter clutch providing means to overrule said automatically operated control means and eiect disengagement oi said torque converter clutch prior to the time said automatically operated con- 17 trol means would effect such disengagement to thereby provide means for the transmission of a torque multiplying drive utilizing the lower ratios of the torque multiplication range of the torque converter.

9. lin a motor vehicle including an engine with an accelerator pedal and a transmission driven by said engine having driving and driven shafts, a hydrodynamic torque converter having a torque multiplication ratio of better than 2.5 to l connectible between said shafts to transmit a torque multiplying drive therebetween, and a clutch associated with said converter adapted to be engaged to provide means for transmitting a positive direct drive between said shafts and to be disengaged to provide means for the transmission of a torque multiplying drive between said shafts through said converter; automatically operated control means responsive to the speed of the driven shaft to condi' on the control system for said clutch for a driver effected clutch engagement after said driven shaft has been accelerated to a predetermined rotative speed, and to automatically effect disengagement of said clutch when the speed ci said driven shaft has decelerated to a speed less than said predetermined rotative speed, a nrst driver operable control means for said clutch adapted to be actuated by release of said accelerator pedal to a predetermined liiniting position to provide a means to effect the engagement of said clutch after said driven shaft has been accelerated to the predetermined rotative speed and a second driver operable control means actuated by depression of said accelerator pedal to a predetermined limiting position to provide a means for manually effecting disengagement of said clutch prior to time said automatically operated control means would effect such disengagement, said rst driver operable means thereby providing a means cooperable with the automatically operated control means to control the period of the torque multiplying rive utilizing the higher torque multiplying ratios of the converter and said second driver operable means providing a means independent of said automatically operated control means to provide a driver operated means for controlling the period of transmission of the positive direct drive and the utilization of the lower torque multiplying ratios of the converter.

1G. In a motor vehicle including an engine with an accelerator pedal a transmission drivingly connected to said engine having driving and driven shafts, a hydrodynamic torque converter connectible between said shafts to transmit a torque multiplying drive therebetween, and a clutch and controls therefor associated with said converter, said clutch being adapted to be engaged to provide means for transmitting a positive direct drive between said shafts and to be disengaged to provide means for the transmission of a torque multiplying drive between said shafts through said converter; said clutch controls comprising a clutch operator and an electrically operated system for actuating said clutch opera-tor and effecting engagement and disengagement or" said clutch, said system having a solenoid unit operably associated with said clutch operator in such a manner that energization and cle-energiz'ztion of said solenoid unit disengages and engages said clutch, and an electrical control system for reflecting energization and de-energization o said solenoid unit comprising first and second solenoid energizing circuits arranged in parallel, said iirst energizing circuit including a Ya clutch. and controls therefor first switch and a governor mechanism responsive to the speed of said driven shaft for auto.- matically opening and closing said :rst switch, said second solenoid energizing circuit including a second switch and a means operable by said accelerator pedal to provide for driver effected opening and closing of said second switch, and a solenoid de-energization circuit comprising said first solenoid energizing circuit and a third circuit arranged in parallel with first solenoid energizing circuit comprising a third switch a ranged to be automatically closed during energization cf solenoid and opened during deenergization of said solenoid, and a fourth switch in series with said third switch, said fourth switch being arranged to be closed during throttle opening movement of said accelerator pedal and to be opened on release of said accelerator pedal to closed or idle thrott e position.

11. In a motor vehicle including an engine with an accelerator pedal and a transmission drivingly connected to said engine having driving and driven shafts, a hydrodynamic torque converter connectible between said shafts to transmit a torque multiplying drive there etween, and kssociated with said converter, said clutch being adapted to be engaged to provide means for transmitting a positive direct drive between said shafts and to be disengaged to provide means for the transmission of a torque multiplying drive between said shafts through said converter; said clutch controls cornprising a clutch operator and an electrically operated system for actuating said clutch operator and effecting engagement and disengagement of said clutch, said system having a solenoid unit operably associated with said clutch operator in such a manner that energization cle-energization of said solenoid unit diseng `ges and engages said clutch, and an electric ,i control tern for effecting energize-tion and de-energization of said solenoid unit comprising a nrst and a second solenoid energizing circuit, circuits being arranged in parallel and each including a switch adapted to be closed to effect energiaation of said solenoid unit, said iirst solenoid energizing circuit having a governor mechanism responsive to the speed of the driven shaft to automatically close he switch in said first solenoid energizing circuit at driven. shaft speed below a predetermined speed and to automatically open the switch in the first solenoid energizing circuit after said driven shaft attains said predetermined speed, said second solenoid energizing circuit including a first accelerator operated switch adapted to be closed by a predetermined movement of said accelerator pedal from the closed throttle position towards the open throttle position and to be opened when the accelerator pedal is released to 'throttle closing position, a `circuit for controlling de-energization of said solenoid unit comprising a solenoid operated switch that is automatically closed upon energization of said solenoid and opened upon daenergization of said solenoid and a second accelerator operated switch in series with said solenoid operated switch, said second accelerator operated switch being arranged such that release of said accelerator pedal to a throttle closing position opens said accelerator operated switch while a predetermined movement of said acceleraor pedal in a throttle opening direction closes said second switch.

l2. In a motor vehicle including engine controlled by an accelerator pedal and a transmission having driving and driven shafts, said driving shaft being connected to said engine, a hydrodynamic torque converter connectible between said shafts to transmit a torque multiplying drive therebetween, and a clutch and controls therefor associated with said converter, said clutch being adapted to be engaged to provide means for transmitting a positive direct drive between said shafts and to be disengaged to provide means for the transmission of a torque multiplying drive between said shafts through said converter; said clutch controls comprising mechanically operated means for eiecting engagement and disengagement of said clutch and electrically operated means for controlling operation of said mechanically operated means, said electrically operated means having a control circuit comprising a irst energizing circuit including means responsive to the speed of said driven shaft to automatically effect disengagement of said clutch when the driven shaft speed decelerates to a predetermined speed, a second energizing circuit for said electrically operated means arranged in parallel with said first energizing circuit and including accelerator pedal operated means to effect activation of said electrically operated means to cause disengagement of said clutch at the will of the ve hicle operator, and a third circuit arranged in parallel With said rst circuit to control the en* gagement of said clutch comprising driven shaft speed responsive means to automatically condition said clutch controls for clutch engagement when said driven shaft has been accelerated to a predetermined speed and accelerator pedal oper ated means to delay the clutch engaging action at the will of the vehicle operator.

13. In a motor vehicle including an engine with an accelerator pedal and a transmission driven by said engine having driving and driven shafts, a hydrodynamic torque converter connectible between said shafts to transmit a torque multiplying drive therebetween, and a clutch and controls therefor associated with said converter, said clutch being adapted to be engaged to provide means for transmitting a positive direct drive between said shafts and to be disengaged to provide means for the transmission of a torque multiplying drive between said shafts through said converter; said clutch controls comprising mechanically operated means for eiecting engagement and disengagement of said clutch and electrically operated means for controlling operation of said mechanically operated means, said electrically operated means having a control circuit comprising a first energizing circuit including means responsive to the speed of said driven shaft to effect activation of said electrically operated means to automatically cause disengagement of the clutch when the driven shaft speed decelerates to a predetermined speed, a second energizing circuit for said electrically operated means arranged in parallel with said first energizing circuit and including accelerator pedal actuable means to eiect activation of said electrically operated means to cause disengagement of said clutch at the will of the vehicle operator, and a third circuit arranged in parallel with said rst circuit to control the activation of said electrically operated means to effect engagement of said clutch comprising driven shaft speed responsive means to automatically condition said clutch controls for clutch engagement when said driven shaft has been accelerated to a predetermined speed and accelerator pedal actuable means operable upon movement of said pedal to a predetermined position to delay the engagement of said clutch at the will of the vehicle operator.

References Cited in the le of this patent UNITED STATES PATENTS Railton June 5, 1951 

